Here's an edited version of a puzzle from the book "Chuck Klosterman four" by Chuck Klosterman.
It is 1933. Somehow you find yourself in a position where you can effortlessly steal Adolf Hitler's wallet. The theft will not effect his rise to power, the nature of WW2, or the Holocaust. There is no important identification in the wallet, but the act will cost Hitler forty dollars and completely ruin his evening. You don't need the money. The odds that you will be caught committing the crime are negligible. Do you do it?
When should you punish someone for a crime they will commit in the future? Discuss.
It will prevent infliction of future negative utility (or at least it is intended to).
So will punishing future crimes. If people see that criminals have a history of being punished in their past "for no reason", they won't wan't to become criminals as much.